Sedges have edges and violets are blue

During the first day of Wetland Plant Identification class we learned a poem.

Sedges have edges
Rushes are round
Grasses are hollow from node to the ground.

The rhyme is supposed to help me get a grip on the distinctions among Cyperaceae, Juncaceae and Poaceae, with emphasis on the plants used by the restoration team at Sheldon Lake. 

Everything that I learned in class each Wednesday was a jumble two hours after I got home. So I was pleased that at least I remembered the poem.

Then I learned there are different versions. Oh, no!

This one is in our notebooks:

Sedges have edges
Rushes are round
Grasses have joints, when the cops aren't around.

A simple search turned up:

Sedges have edges
Rushes are round
Grasses have nodes where leaves are found.

Sedges have edges
Rushes are round
Grasses have joints that your friends pass around.

Sedges have edges and other things. White-topped sedge: Rhynchospora colorata / Dichromena colorata

Sedges have edges
Rushes are round
Grasses have joints where elbows are found

What the what?

Here's my version:

Sedges have edges
Rushes are round
Grasses have nodes, moron.

- Lana b.